© 2016

The Germ of an Idea

Contagionism, Religion, and Society in Britain, 1660–1730

  • Authors

Table of contents

  1. Front Matter
    Pages i-xxi
  2. Margaret DeLacy
    Pages 17-35
  3. Margaret DeLacy
    Pages 67-83
  4. Margaret DeLacy
    Pages 147-169
  5. Margaret DeLacy
    Pages 171-175
  6. Back Matter
    Pages 177-305

About this book


Germ of an Idea shows how a belief in contagion began to spread among a group of medical reformers who had been forced by nationality and religious nonconformity to follow alternative pathways to medical education and professional status in early eighteenth century Britain. It explains how contagionism shaped their ideas about the nature and behavior of diseases such as smallpox, plague, syphilis, and consumption and how it interacted with the belief that diseases were not imbalances, but specific entities.


Britain eighteenth century English Europe event Great Britain history idea medicine modern history religion seventeenth century society understanding writing

About the authors

Margaret DeLacy is an independent scholar. She received her Ph.D. in British history from Princeton University, USA. She is the author of Prison Reform in Lancashire, 1700-1850: A Study in County Administration and several articles on British medical history.

Bibliographic information

  • Book Title The Germ of an Idea
  • Book Subtitle Contagionism, Religion, and Society in Britain, 1660–1730
  • Authors Margaret DeLacy
  • DOI
  • Copyright Information The Editor(s) (if applicable) and The Author(s) 2016
  • Publisher Name Palgrave Macmillan, New York
  • eBook Packages History History (R0)
  • Hardcover ISBN 978-1-137-57527-2
  • Softcover ISBN 978-1-349-57558-9
  • eBook ISBN 978-1-137-57529-6
  • Edition Number 1
  • Number of Pages XXI, 305
  • Number of Illustrations 0 b/w illustrations, 0 illustrations in colour
  • Topics History of Britain and Ireland
    History of Science
    History of Medicine
  • Buy this book on publisher's site


“This is a well-researched book by independent scholar DeLacy, citing materials from an extensive array of scholarly medical collections, many from the United Kingdom. … In The Germ of an Idea, Dr. DeLacy seems to have done a notable job of connecting many of those medical history dots characterizing the years 1660-1730 in England and bringing them into a more focused image.” (Sharon Butcher, The Watermark, Vol. 42 (4), 2019)

“The book is a serious contribution to the study of Cartesian physiology in the seventeenth century and beyond. … it certainly contains essential reading for scholars of Cartesianism.” (Klaas van Berkel, ISIS, Vol. 109 (1), March, 2018)

“This review cannot do justice to the incredible level of detail displayed in this book … It provides scholars of the history of early modern medicine and science, and of cultural and social history, with an excellent insight into London in the late seventeenth and early eighteenth centuries and in doing so draws our attention to the nexus linking religious and political beliefs, on the one hand, with medical ideas, on the other.” (Sietske Fransen, ISIS, Vol. 108 (4), December, 2017)

“The Germ of an Idea provides a useful account, based on exhaustive research, of a fascinating moment in British medical history. Most striking is DeLaey's demonstration of how social and political factors underwrote both the articulation of contagionist theories and the opposition to them." (John Waller, Journal of the History of Medicine and Allied Sciences, October, 2017)

"Overall DeLacy accomplishes an amazingly comprehensive and succinct survey in fewer than two hundred pages." (Ann G. Carmichael, American Historical Review, Vol. 122 (3), June, 2017)

"Margaret DeLacy has been studying the early roots of contagion theory for many years and has now produced the most important book on the topic to appear for quite some time." (Kevin Siena, Bulletin of the History of Medicine, vol. 91 (2), 2017)

“The book’s importance to historians of this era and medical historians especially is self-evident, because it occupies a lacuna in the scholarship. … Although this book is written for scholarly audiences and densely packed, it is clear and accessible to general readers with avid interest in medical history. For Health Humanities professionals, this book underscores–with a twist–one of the primary lessons we hope to teach our medical students.” (Sandra G. Weems, MedHum Daily Dose,, June, 2016)